Toxicological assessment of diphenyl ether using adult zebrafish and human lymphocytes: Biochemical, genotoxic, cytotoxic, histopathological and ultrastructural analysis

In the present investigation, the toxicological impact of diphenyl ether (DE) was assessed in gills and blood of adult zebrafish through biochemical, genotoxic, histopathological and ultrastructural analysis. Moreover, in human lymphocytes, toxic effects of DE were evaluated using in vitro assays such as chromosomal aberration and cytokinesis-block micronucleus (CBMN) assay. The exposure concentrations of DE used for the toxicity assessment were 2.13 mg/L (¼ LC₅₀) and 4.25 mg/L (½ LC₅₀) for zebrafish as well as human lymphocytes. Significant changes in the biochemical parameters such as SOD, GST, AChE activity and MDA levels were reported after DE exposure in zebrafish gill. The olive tail moment (OTM) was found to be significantly increased in gill and blood cells of DE exposed zebrafish. The MN assay revealed significantly elevated frequency of erythrocytic cytoplasmic abnormalities (ECA), erythrocytic nuclear abnormalities (ENA) and micronuclei (MN) in the DE exposed zebrafish. Various types of histopathological alterations were reported in gill tissue of zebrafish exposed to DE which were further confirmed through SEM analysis. The SEM analysis of erythrocytes of zebrafish exposed to DE revealed the morphological alterations such as irregular shaped erythrocytes with irregular boundaries, swollen erythrocytes etc. Moreover, In vitro assay such as chromosomal aberration assay showed the different types alterations such as polyploidy, satellite association, telomeric association and chromosomal breakage in human blood cells exposed to DE. Different kinds of abnormalities such as multiple nucleated cells, late apoptotic cells, micronucleated cells etc. were reported after DE exposure to human lymphocytes.